A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

An apparatus and a method for optimized calculation of 2D sub-holograms for object points of a three-dimensional scene and a pipeline for real-time calculation of holograms are provided. The invention shortens the calculation time of a hologram for representing a three-dimensional scene and/or to reduce the calculation complexity of such a hologram. This is achieved by a 2D sub-hologram of an object point, which has image elements of the spatial light modulator, comprises a half 1D sub-hologram, where the radius of each image element is determined and each image element of the 2D sub-hologram is fixedly assigned to at least one image element of the half 1D sub-hologram with identical or similar radius by way of an electronic circuit, by a method for encoding a hologram, and by a pipeline on the basis of FPGA and/or ASIC.

Architecture and designs of modulating both amplitude and phase at the same time in spatial light modulation are described. According to one aspect of the present invention, light propagation is controlled in two different directions (e.g., 0 and 45 degrees) to perform both amplitude modulation and phase modulation at the same time in liquid crystals. In one embodiment, a mask is used to form a pattern, where the pattern includes an array of alignment cells or embossed microstructures, a first group of the cells are aligned in the first direction and a second group of the cells are aligned in the second direction. Depending on applications, two cells from the first group and the second group may correspond to a single pixel or two neighboring pixels, resulting in amplitude modulation and phase modulation within the pixel or within an array of pixels.

A three-dimensional light modulator, of which the pixels are combined to form modulation elements. Each modulation element can be coded with a preset discrete value such that three-dimensionally arranged object points can be holographically reconstructed. The light modulator is characterized in that assigned to the pixels of the modulator are beam splitters or beam combiners which, for each modulation element, combine the light wave parts modulated by the pixels by means of refraction or diffraction on the output side to form a common light beam which exits the modulation element in a set propagation direction.

A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

The invention relates to a display device for holographic reconstruction. The display device comprises a spatial light modulator device having combined phase modulating pixels and amplitude modulating pixels, an illumination unit generating sufficiently coherent light and arranged to illuminate of the spatial light modulator device and a reflection plane. The device being arranged such that light enters the spatial light modulator device and passes both the phase modulating pixel and the amplitude modulating pixel of the spatial light modulator device. The light is reflected by the reflection plane in between.

An apparatus and a method for optimized calculation of 2D sub-holograms for object points of a three-dimensional scene and a pipeline for real-time calculation of holograms are provided. The invention shortens the calculation time of a hologram for representing a three-dimensional scene and/or to reduce the calculation complexity of such a hologram. This is achieved by a 2D sub-hologram of an object point, which has image elements of the spatial light modulator, comprises a half 1D sub-hologram, where the radius of each image element is determined and each image element of the 2D sub-hologram is fixedly assigned to at least one image element of the half 1D sub-hologram with identical or similar radius by way of an electronic circuit, by a method for encoding a hologram, and by a pipeline on the basis of FPGA and/or ASIC.

A reflective holographic display apparatus and a display method thereof are disclosed. The reflective holographic display apparatus includes a front light source module, a display panel and a phase plate. The front light source module is configured to provide reference lights; the display panel is configured to adjust amplitude information of the reference lights, wherein the display panel includes a reflective layer and the front light source module is located at a light exit side of the display panel; and the phase plate is configured to adjust phase information of the reference lights and located at a light exit side of the reflective layer.

In the present invention, by providing an apparatus for displaying a complex modulated holograph and including a light source configured to output light, a display configured to display the hologram by diffracting the output light through a plurality of pixels, and a processor configured to control the display to obtain complex hologram data corresponding to the hologram, and modulate the output light based on the complex hologram data and device information of the plurality of pixels, it is possible to modulate amplitude information and phase information of the light source into required values and display a complex hologram, and to remove a noise component of the hologram.